This book describes the construction of a complete chamber organ with four registers. The starting point was that someone who wants to build a chamber organ does not have to delve into superfluous organ theories first, but is sufficiently informed with clear drawings of the various parts.
Detailed drawings in perspective and photographs are the language of this book as the shortest way to the practical construction of a chamber organ. The disposition is a Stopped Diapason 8’, a Rohrflute 4’ and a Flute 2’ who’s bass and the treble are separate to choose plus a Quint 3 ' as coloring treble register.
In this book, the creation of a full chamber organ is described in detail. It is meant as well for a beginner, because experience with the building of organs is not a condition and also for people who have already built a small organ and wants now an organ with more registers. All pipes are made of wood. Each component is accurately drawn in perspective, as if it was photographed. These three-dimensional drawings are easily understood by the organ builder.
A Stopped Diapason 8’ (flute sound) is the perfect base sound and can be supplemented by a four-feet register. Often this is a Rohr Flute 4’, but it is the same flute sound again. A Principal 4’ is better; with his singing sounds it is the ideal complement to the eight foot base sound. This register is described in detail in the book to use it in a small organ.
In the time of the Cabinet organs, the Secretary organ was a popular organ. It didn't need a dominant place in a living room. The large octave of Principal 4’ is stopped and this gives a Quintaton-like sound. A Principal 4’ is best made of metal. This fits very well with lead from the hardware store or the plumber. When is chosen for organ metal, a very high lead content (95 to 98%) is observed.
Although a Principal cannot actually be made of wood, the construction of the historical organ of the Silver Chapel in Innsbruck is described here. This is the best approach to the sound of a wooden pipe. Anyone who wants to make all the pipes out of wood can do this, both constructions are described in detail in this book. Besides these two registers there is still space for a Nasard 3 ' as a treble register. The book also provides a clear description of both wood and metal pipes.
The first edition of the book appeared in 2003 and since then hundreds of organs have been built worldwide of this design. It shows that building an organ is possible for people at any age and that women are also to do so.
Building an Positive organ is for people who have experience with the construction of organs and now want to learn the design of an organ at the level of an expert. The formation of the sound is treated here. The sound of an organ is the sound of the different registers together which all add their own timbre to the consonance.
The names of the registers are often derived from musical instruments that make a similar sound. This does not apply to the Principal 8’, which is the very own sound of an organ that has no affinity with an orchestral instrument. However, there is some agreement with the choir vocals.
The mathematical knowledge needed to calculate the correct scale for the sound of a pipe is treated in this book. Then the builder learns how with this scale a pipe made of metal is made, which lets you hear exactly the desired sound. Wooden pipes are only suitable for overtone-poor sounds like the Stopped Diapason and the Subbass. Besides the design of 24 registers, an effective construction of a roller board is also drawn.
The most popular type is the barrel organ with music rolls made of paper. Several companies offer a wide range of music roles for this organ. It is also possible to punch music rolls with simple means. In this book the construction of a barrel organ is explained step by step.
1. Pneumatics
In a barrel organ the music role takes over the work of the organist. Which valve opens is determined by the hole in the roll. The system uses air pressure differences and that is called pneumatics.
2. Tracker bar
This part translates the holes of the roll into applying for the pipes. A hole means that the pipe is sounding.
3. Windchest
The wooden organ pipes are located on a windchest. Here are the membrane valves that switch the sound of the pipe on or off. There are two windchests in this organ. One for the bass pipes hanging under the instrument and a windchest for the melody pipes in the front.
4. Pipes
Barrel organs have their own characteristic sound. Often amateur builder make the mistake to construct pipes, which are intended for a chamber organ. It is possible, but then it has not the characteristic sound of the barrel organ. For three years I learned how to make this sound from barrel organ builders in the Black Forest and at the company Raffin on Lake Constance. The construction of these pipes is described in this chapter.
5. Bellows
The rotating movement necessary to pull the music roll over the tracker bar also serves a few bellows that fill the Magasinbalg.
6. Organ cabinet
The parts described above are placed in the organ cabinet. The sound of the pipes is more beautiful when they fuse together in an organ cabinet. For better accessibility, the cabinet is executed here as a framework closed with separate panels.
All parts are described in the sequence of construction. When the builder finishes the last page, the barrel organ is ready.
The room in which a church organ is located differs considerably from the room around a chamber organ and that implies large differences between the two types of organs. It can accompany a choir or be part of a small orchestra, after that the organist takes the organ to his house to study at home.
Often the mistake is made to cram a chest organ with registers, too many pipes in too small a space, both at the expense of the sound. It is better to have one Stopped Diapason 8’ of ample scale, then try to produce enough sound with many pipes of scary scale. The scale of the Stopped Diapason 8’ is chosen so that the Register has sufficient capacity to support a choir or to use as a continuo instrument. By closing the case completely, the organ is not too loud in the interior. Opening the doors gives a strong reinforcement of the sound.
In addition to a Stopped Diapason 8’, the second register is often chosen as a Rohr Flute 4’, but the sounds differ too little from each other. The second register must have a good contrast to the Stopped Diapason 8’ and still be able to merge completely. A conical flute in the treble meets this desire in an ideal way. The wooden pipes easily allow a conical construction shape. The bass pipes are built as Quintaden, who’s singing muted bass pipes go unnoticed into the conical flute sound. The register adds hue and brightness to the Stopped Diapason 8’ and makes a quint and a two feet register superfluous. Both registers mix together to a sound.
The organ is two-piece, in the cupboard there is room for the electric motor and the bellows with the sturdy curtain control next to a few bass pipes. The remaining bass pipes are located behind the upper casing.
Besides playing of a Hauptwerk organ is making music on a small organ with real pipes also a pleasure, provided the organ has a full sound. One register is sufficient if it has a clear sound plus a deep basic tone. Then the sound doesn’t differ from a larger organ. A beginner can build this Table Positive easily and by its small weight the organ can be taken to the rehearsals of a choir. It is also useful for the accompaniment of a soloist.
According as an organ has a larger tone size, the complexity of the construction increases. If the width of the pipe allows it to be placed directly behind the corresponding key, a simple connection between the key and the valve is possible. Pipes for lower tones require more space. It does not make sense to place pipes of small size because that is at the expense of a beautiful sound.
When designing this organ I have played a lot on large organs, taking into account the lowest and highest tone needed for the music. Also the playing of old organs gave an indication; the visible wear on the keys showed which keyboard size was usually used. The conclusion was that a keyboard size of F minor to d3 does not impose too many restrictions. The pipes have the same scale as the pipes of my chamber organ.
